1. Field of the Invention
The present invention relates to an illuminating device, and in particular to an illuminating device structure which makes it possible to make the whole thickness thinner as such to obtain a high illuminating efficiency in such a way to remove a light guide plate and makes it possible to obtain an effect that the shape and a 3D effect of light change by forming a protrusion optical pattern.
2. Description of Related Art
The LED (Light Emitting Diode) device is directed to converting an electric signal into infrared ray or light using the natures of a compound semiconductor. Different from a fluorescent lamp, it does not use any harmful substances such as mercury, which results in less environment contamination, along with an advantage that service life is longer as compared to a conventional light source. It also consumes low electric power as compared to a conventional light source, and visibility is good thanks to a high color temperature and no glaring.
The illuminating device is currently changing from a type that a conventional incandescent lamp and a conventional fluorescent lamp are used as a light source to a type that a LED device is used as a light source. In particular, there is provided an illuminating device which performs a plane light emitting function by using a light guide plate as disclosed in the Korean Patent Publication number 10-2012-0009209.
FIGS. 1 and 2 are schematic views illustrating a conventional illuminating device 1 which can provide a plane light emitting function. As shown in FIGS. 1 and 2, the conventional illuminati device 1 is configured in such a way that a flat light guide plate 30 is arranged on a substrate 20, and a plurality of lateral type LEDs (only one is shown in the drawing for simplification) is arranged at a side of the light guide plate 30.
The light inputted from the LED 10 into the light guide plate 30 is reflected upward by means of a fine reflection pattern or a reflection sheet 40 which is disposed on a bottom surface of the light guide plate 30 and is emitted from the light guide plate 30, so the light can be emitted to the outside by way of an external housing 50, etc. which is made from a transparent material. As shown in FIG. 2, the above mentioned illuminating device 1 further features in that a plurality of optical sheets such as a diffusion sheet 31, prism sheets 32 and 33, a protection sheet 34, etc. are disposed between the light guide plate 30 and the external housing 50.
Here the illuminating device 1 serves to uniformly supply light to the outside, and the light guide plate 30 serves to enhance the luminance of the illuminating device 1 while ensuring that a uniform light can be supplied. In other words, it is a kind of a plastic formation lens configured to uniformly transfer the light emitted from the light source (LED). So, the above mentioned light guide plate 3 is used as a necessary element of the conventional illuminating device 1; however it has a limit in making a thinner product owing to the thickness itself of the light guide plate 30. Since the material of the light guide plate 30 is not flexible, it cannot be applied to the external housing 50, etc. which has curved surfaces, so the product design and the design changes are not easy.